The 18-year-old Van der Linde and his experienced 27-year-old German team-mate won both one-hour races that made up the seventh round, taking the honours in race one on Saturday, after starting from pole position, by 1,3 sec from Christian Engelhart of Germany and nearest championship rival, Jaap van Lagen of Holland, in a Porsche 911 GT3.

Pole-sitter van der Linde needed nerves of steel in the first half of the race. The Audi driver converted pole position into a race lead, but then saw it whittled away by two safety car periods in the first seven laps. The yellow flags first came out after a collision on the opening lap and again on lap 6 after a mechanical breakdown left a car stranded in the middle of the track. Rast took over in the lead and also had safety car periods to contend with, but fought off a determined challenge from Engelhart to take a narrow victory.

“This second victory of the season was a lot longer coming than we had wanted,” said a beaming Van der Linde after the race. “We are very pleased to have finished ahead of our closest pursuers – this gives us a bit more breathing space at the top.”

They started from third place on the grid in today’s race, with Rast at the wheel for the first half hour. He handed over to his young South African team-mate in the lead and Van der Linde almost immediately had to contend with rain that had earlier affected the qualifying session on Friday.

Then the rear diffuser of the Audi fell off and he had to use all his skill and fighting spirit to keep the rest of the field at bay. He eventually crossed the finish line 2,2 sec ahead of Robert Renauer and Dominik Schwager of Germany (Porsche (911 GTR 3) and 6,3 sec ahead of Prosperia C. Abt Audi team-mates Fabian Hamprecht of Germany and Nicki Thiim of Denmark.

With one round and two one-hour races remaining, and a maximum of 50 points on offer, the South African/German duo leads Jaap van Lagen by 35 points (205-170) and Claudia Hürtgen of Germany and Dominik Baumann of Austria by 46 points (205-159). The final round is at the Hockenheimring in Germany on October 4 and 5.